Mobile Suit Gundam Silhouette Formula 91 in U.C. 0123

Universal Century 0123. In the midst of doing simulations, pilots Tokio and Kevin Forrest encounter an XM-01 Den'an Zon Mobile Suit running tests for the nearby Crossbone Vanguard. In order to preserve their secrecy, the Crossbone forces attack the Anaheim test ship Bladewood. They expect an easy victory, but are repulsed by the Bladewood's mobile suits. In order to enact repairs from the damage they sustained at the hands of the Crossbone Vanguard, the Bladewood enters a nearby abandoned space colony in the Zebra Zone.

Inside the colony Iris, Tokio and Kevin are attacked by a Geara Doga. They successfully capture the machine and find the pilot to be a young girl by the name of Layla Lagiorr. After initially remaining silent she has an emotional outburst in which she explains that there are Zeon Remnants living in the colony and that six years ago the Federation came and slaughtered most of them.

Confused by her story the Bladewood's crew decide to attempt to contact the Zeon Remnants and attempt to ascertain what is going on. They do so and discover the harsh reality of Federation forces that relishes killing the remnants of Zeon in a way similar to the Titans. Meanwhile the Ra Cailum class ESFS starship Ajax arrives at the colony in order to "aid in repairs" and transfer personnel under the command of Baz Galemson. Together the Zeon Remnants and the crew of the Bladewood realize that the situation surrounding them is not as it seems. Eventually, it is revealed that the crew of the Ajax knew of the existence of the Crossbone Vanguard and requested their help in "killing 2 birds with 1 stone", namely a group of Zeon refugees and the Bladewood crew. In desperation, Tokio steals the RX-99 Neo Gundam Unit 2 and joins forces with Layla to take down the corrupt Baz and the Ajax.